For processing disk-shaped semiconductors, for example for etching silicon disks (wafers), possibly using different acids, positioning the semiconductor on a rotating carrier (chuck) is known. A treatment liquid, for example an acid, is applied to the surface of the semiconductor to be treated. The etching liquid distributes itself over this surface due to the rotational movement of the semiconductor and is accelerated laterally (radially) over the edge of the semiconductor.
For catching this treatment liquid, it is suggested, in European Patent 0 444 714 B1, that at least two ring channels, which are open to the inside of the receptacle, be provided in the annular receptacle (pot) for collecting the treatment liquid. In other words: the ring channels are used for the purpose of catching thrown-off processing liquid. Accordingly, the ring channels are arranged in the receptacle in a radial extension of the semiconductor to be treated. In German Patent Application 198 07 460 A1, an annular receptacle of this species is described which has, in addition to the annular channel, via which the treatment liquid is removed, at least one suction device. The basic idea of this known solution is to suction off the processing air (processing gas) located in the system (the facility) separately from the radial absorption of thrown-off processing liquid.
However, due to the essentially rotationally symmetric construction of the receptacle, the problem of non-uniform suction performance results if, as suggested in German Patent Application 198 07 460 A1, the processing air collected in the ring channel is suctioned off via a radially running connection line. In addition, the known receptacle is relatively large. Space problems result from this in clean rooms, where these types of devices are installed. The space necessary for a device is a not insignificant influencing dimension for the overall production costs.
Finally, the known device requires, due to differing pressure ratios (considered over the circumference of the device), a relatively high suction power which may, for example, be up to 1000 m3/h for wafers having a diameter of 30 cm.
The present invention therefore has the object of constructively optimizing a device (receptacle) of the type described in order to fulfill at least one, preferably all, of the following criteria:
The device is to be as small as possible for a defined size of the objects to be treated,                pressure conditions which are as uniform as possible (considered around the circumference of the device) are to be sought in regard to the respective suction device,        the necessary suction power is to be as low as possible for reasons of cost,        separation of different treatment media, including the respective processing atmosphere, which is as precise as possible is to be sought.        
To achieve these and further parts of the object, which result from the remaining application documents, the present invention is based on the following basic consideration: in an essentially rotationally symmetric component, such as a receptacle according to the species, uniform pressure ratios may not be achieved in the receptacle with a more or less punctually acting partial vacuum source if the individual supply lines discharge directly into a joint peripheral channel, which the suction line leads away from.
In contrast, the pressure ratios are greatly improved if the atmosphere to be removed is initially led into a suction chamber and from there into a pressure distribution chamber, to which a suction line is connected.
The advantages connected with this are particularly clear in “multistory receptacles”, i.e., devices in which the carrier for the object to be treated is vertically displaceable and different treatment processes are performed at various vertical heights. Thus, for example, in one step a wafer may be etched, and in another step the wafer surface may be washed using deionized water. In this case, annular channels corresponding to each treatment step are assigned, via which the respective processing liquid may be removed. Each annular channel is then in turn assigned a suction device, which is implemented in the way described in the preceding and following. Multiple suction devices preferably discharge into one and the same pressure distribution chamber, which causes the suction power to even out, the corresponding partial vacuum able to occur via a central suction line, as in the related art.